Kevin's dog Buster will not stop barking, so his family leaves it up to him to take him to the vet. But the veterinarian Dr. Ferleger's (Christine Rose) solution to the situation chills Kevin to the bone and everyone leaves it up to him to decide on what to do. Kevin even seeks the help of his senile shop teacher Mr. Nestor but he only reminisces about his old dog Smokey. Meanwhile, Buster's misbehavior continues when he chews up Jack's important work reports. Kevin takes Buster to the park, but he finds a female dog and runs away, leaving the family to search for him later. They soon realize that Buster is a part of the Arnold clan too--their "silent partner".